Tape cartridge automatic exchange device

ABSTRACT

A tape cartridge automatic exchange device for automatically supplying a number of magnetic tape cartridges stacked in a magazine to a predetermined playing or recording position one after another for playing or recording, in such a manner that the lowermost tape cartridge is placed in said playing or recording position, removed from said position upon completion of the playing or recording and then the next tape cartridge is placed in said position.

United States Patent [72] Inventors lsarnu Takagi; [50] Field 271/3 X,Atushi Shino, both of Tokyo, Japan 44 X; 242/198, 199, 208; 179/1002 Z;274/4 BCF, [21] 699,595 11 BC; 353/1 1 1, 1 12; 352/123, 6-8; 221/236,

Appl. No. [22] Filed 1 Jan. 22, 1968 Patented June 1, 1971 [5 6]References Cited UNITED STATES PATENTS 173] Assignee Aiwa Co.,Ldt.

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ABSTRACT: A tape cartridge automatic exchange device for automaticallysupplying a number of magnetic tape cartridges stacked in a magazine toa predetermined playing or recording [54] TAPE CARTRIDGE AUTOMATICEXCHANGE DEVICE position one after another for playing or recording, insuch a manner that the lowennost tape cartridge is placed in saidplaying or recording position, removed from said position uponcompletion of the playing or recording and then the next tape cartridgeis placed in said position.

3 Claims, 21 Drawing Figs. [52] 274/4, 221/236, 221/293, 352/8, 352/123,242/200 [51] Int. Gllb 5/00 PATENIEDJUN nan 3582.082

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sum 1DUF12 PATENIED Jun nan saw 12 0F 12 TAPE CARTRIDGE AUTOMATICEXCHANGE DEVICE The present invention relates to a tape cartridgeautomatic exchange device adapted to be used with a magazine-type taperecorder, by which a number of tape cartridges stacked in a magazine areplayed or recorded one after another in sequence automatically from thelowermost one of said cartridge stack and which comprises a baseplatedisposed below the magazine, a pair of cooperating swinging armspivotally connected to the top surface of said baseplate with apredetermined space therebetween, a reciprocating sliding platelaterally slidably disposed below said baseplate and having atape-cartridge-receiving hole formed therein, a guide member disposedbelow said sliding plate, another pair of cooperating swinging armspivotally connected to the top surface of said guide member with apredetermined space therebetwecn, a drive motor to cause a lateralsliding movement of said sliding plate, a switch to interrupt thecurrent supply to said drive motor, another switch to reverse therotation of said drive motor and still another switch to reset saiddrive motor in operation upon completion of the playing or recording ofa tape cartridge, the arrangement being such that when the drive motoris set in motion, the sliding plate is moved laterally opening orrecording position, whereupon the'current supply to the drive motor isinterrupted automatically by said first switch to hold the tapecartridge in said position and said second switch is actuated to providefor a reverse rotation of the drive motor, following which the tape inthe cartridge is trailed along the magnetic head and the capstan on theassociated tape recorder and pressed by a pad and a pinch roller eithermanually or automatically for playing or recording, and upon completionof the playing or recording, said third switch is actuated either byactuating means such as a plunger adapted to detect the completion ofthe playing or recording or by manual operation, whereby the drive motoris set in motion again but. rotating in a reverse direction, so thatsaid sliding plate is returned to a point approximating to the originalposition with the used tape cartridge therein, whereupon the pair ofswinging arms on the guide member are opened'by said sliding plate andthe used tape cartridge is dropped gravitationally downwardly of theguide member, said sliding plate thereafter being further moved slightlylaterally and then set in its forward stroke for carrying the next tapecartridge to the playing or recording position.

For a better understanding of the present invention, reference will nowbe made, by way of example, to the accompanying drawings, in which:

FIG. 1 is a perspective view, partly broken away, of the tape cartridgeautomatic exchange device according to the present invention;

FIG. 2- is a perspective view, partly broken away, of the device of thisinvention in a position different from that shown in FIG. 1;

FIG. 3 is an enlarged perspective view showing an example of the tapecartridge to be used with the device of this invention;

FIGS. 4 and 5 are enlarged plan views, partly broken away, of theinventive device in the positions shown in FIGS. 1 and 2 respectively;

FIG. 6 is an enlarged plan view, partly broken away, of the inventivedevice in still another position;

FIGS. 7 and 8 are vertical cross-sectional views taken along the linesVII-VII in FIG. 4 and the lines VIII-VIII in FIG. 6 respectively;

FIGS. 9, 10, 11 and 12 are perspective views of a tape cartridgemagazine, a mounting baseplate, a sliding plate and a tape cartridgeguide member respectively;

FIG. 13 is an enlarged perspective view showing the critical portion onthe underside of the sliding plate shown in FIG. 11;

FIG. 14 is an exploded perspective view of the portion of the slidingplate shown in FIG. 13, in which A denotes an end portion of the slidingplate, B denotes a rocking member, C denotes a hooking member, D denotesa coil spring and E denotes a snap spring;

FIGS. 15 and 16 are enlarged perspective views of swinging armsrespectively;

FIGS. 17 to 20 inclusive are fragmentary enlarged bottom views ofone-half side of the inventive device respectively, illustrating theoperation of the portion of the sliding plate shown in FIG. 13; and

FIG. 21 is a wiring diagram showing an example of the drive motorcontrol circuit.

Referring to the drawings and first to FIG. 10, a mounting baseplate lis made of a metal sheet and has a relatively large rectangular hole Informed in the right side portion thereof. Adjacent the four corners ofthe rectangular hole Ia are provided four upstanding cylindrical bossesIA. A magazine 3 for the storage of a stack of tape cartridges 2, 2, oneof which is shown in FIG. 3, has both the top and bottom ends open andis fixedly mounted on a guide plate ,4 as shown in FIG. 9. The guideplate 4 has a guide hole therein with downwardly bent lugs 4A formed atthe edges of said hole, and is fixedly mounted on the aforementionedupstanding bosses IA on the baseplate I in spaced, substantiallyparallel relation to said baseplate. A pair of cooperating substantiallyL-shaped swinging arms 5, 5 are pivotally mounted at their flexedportions on respective pivot pins 5 5,, provided adjacent the right sideend comers of the baseplate 1, in such a manner that their cooperatingends will block the passage in the rectangular hole la from the oppositesides of said hole to support a tape cartridge thereon. As best shown inFIG. 16, the swinging arms 5, 5 are each provided at the other endthereof with a downwardly projecting pin 5A, which is extending througha slot lb formed in the baseplate 1, and are biased towards each otherby respective springs 6, 6 as shown in FIG. 10, with their cooperatingends urged inwardly of the rectangular hole 1a in the baseplate 1. Thebaseplate 1 is also formed therein with a substantially T-shaped slot 1cand elongate slots 1d, 111 on both sides of and in parallel to saidT-shaped slot 10, all of which slots are extending from substantiallythe center towards the left or rear end of the baseplate 1. A slidingplate 9, as shown in FIG. 11, has a rectangular hole 9a formed thereinwith pairs of confronting downwardly bent lugs 9A formed along the edgesof said hole. This sliding plate 9, as shown in FIGS. 7 and 8, isdisposed below the baseplate l in adjacent parallel relation thereto andis connected to a rack 7 by means of bolts 8A, 8A extending through theguide slot 1c in the baseplate 1 and washers 8, 8 interposed betweensaid rack and the baseplate with the free ends thereof screw threadedinto said rack. Thus, it will be understood that the sliding plate 9 isslidable along the guide hole 10 in the baseplate 1 integrally with therack 7. The rack 7 is meshing with a step gear 10 to be operatedthereby, which step gear 10 is rotatably supported by a pair of L-shapedbrackets 11 fixed on the baseplate 1 as best shown in FIG. 2. The stepgear 10 in turn is in engagement with a pinion 12 which is mounted onthe driving shaft of a reduction gearing 14. The reduction gearing 14 isoperatively connected to the driving shaft m of a drive motor M by meansof a belt 13, said reduction gearing 14 and said drive motor M beingmounted on an L-shaped bracket 15 fixed on the rear end portion of thebaseplate 1. The sliding plate 9 is also provided at substantially thecenter thereof with guide bosses 16, as best shown in FIG. 7, which areextending upwardly through the respective elongate slots 1d, lid in thebaseplate l for a sliding movement therein so as to guide the slidingmovement of said sliding plate. On the top ends of the guide bosses 16,16, extending above the baseplate l, is mounted a U-shaped member 17which has its arms extending rightwardly for reciprocal movement intoand from the tape cartridge containing magazine 3, as shown in FIGS. 7and 10. When the sliding plate 9 is moved to the right, the arms of theU-shaped member 17 project into the magazine 3,

as shown in FIG. 6, through respective slots 3a in the wall of themagazine shown in FIG. 9, to thereby prevent the downward movement ofthe tape cartridges in the magazine, except the lowermost one, in themanner shown in FIG. 8. On the front sidewall 7, of the rack 7 arefitted switch-actuating projections 7A, 78, as best shown in FIG. 5, forthe actuation of a drive motor control switch to be described later.

Below the sliding plate 9 are arranged in spaced parallel relationthereto a substantially U-shaped guide member 18 and a substantiallyrectangular guide plate 19, which are secured to the downwardlyextending bosses 1B, 1B of the baseplate 1 as shown in FIGS. 2 and 7.The guide member 18, as best shown in FIG. 12, is formed of confrontingupwardly bent lugs 18A for guiding the tape cartridge, whereas the guideplate 19, as best shown in FIG. 12, is provided with a pair of parallelguide rails 19A, 193 at the opposite edges thereof. The guide member 18also has a pair of substantially Z-shaped swinging arms 20, 20 providedon the root portion thereof in symmetrical relation. These swinging arms20, 20 are pivotally mounted on respective pivot pins 20,, 20, on theguide member and formed of upwardly bent lugs 20A, 20A respectively at alocation adjacent to the respective pivot pins. The ends of the arms 20,20 which are closer to the pivot pins 20,, 20, are biased outwardly bymeans of respective springs 21, 21 which have one end connected to pins20B, 20B on said respective arms and the other end to the guide member18, so that the other ends of the arms 20, 20 are urged towards eachother to cooperatively support the tape cartridge 2.

As shown in FIG. 11, in the forward or right side edge 9, of the slidingplate 9 are formed U-shaped guide notches 9b, 9b in symmetrical relationwith respect to the centerline of said sliding plate. The sliding plate9 also has downwardly projecting bosses 9B, 98 on the underside thereof,on each of which a substantially L-shaped rocking member 22, indicatedat B in FIG. 14, is pivotally mounted with said boss extending through ahole 224 formed in said rocking member. Each of the rocking members 22is provided with a pin 22A, to which a tension spring 23, indicated at Din FIG. 14, is connected at one end, the other end of said tensionspring being connected to a pin 90, provided on the sliding plate 9adjacent to the forward edge 9, of the sliding plate, as shown in FIG.13. The rocking member 22 is also provided at one end with a boss 22Bprojecting downwardly from the underside thereof and a hooking member24, indicated at C in FIG. 14, is pivotally mounted on said boss 228 ata hole 24a. A snap spring 25, indicated at E in FIG. 14, is mounted onthe downwardly projectingboss 228 on the rocking member, with one endbearing against a downwardly bent lug 24A of the hooking member and theother end against a downwardly bent lug 220 of the rocking member 22 ina manner as shown in FIG. 13.

Now, the control circuit for the drive motor M will be explained withreference to FIG. 21. The terminals 1,, t of a DC power source arerespectively connected to the outer fixed contacts S,,,,' S and theinner fixed contacts S S of a polarity-changing switch S of the bipolardouble-throw type. The movable contact strip 8,, of the switch S isconnected to another movable contact strip S of said switch S through aparallel circuit composed of switches S, and 5,,, and the drive motor Mis connected to said parallel circuit in series. The movable contactstrips 5,,, and S of the switch S have their end tips connected to asingle connecting rod S, of electric insulating material forsimultaneous switching operation. The connecting rod S, in turn isoperatively connected to a switching strip extending from substantiallythe center of the body of the switch S by means of a compressed spring SWith the arrangement described, when the switching strip S is operatedby the switch-actuating projection 7A or 78 on the rack 7 to thesolid-line position to the dotted line position shown in FIG. 21 or viceversa, the connecting rod S, and therefore the movable contact strips SS are moved in a direction opposite to the moving direction of theswitching strip S by virtue of the compressed spring 5,. The swingingmotion of the switching strip S, is limited by respective stopper plates5,, 8,.

The device of the present invention constructed as described hereinabovewill operate in the following manner, Namely, first of all the rack 7,the sliding plate 9 and the U- shaped member 17 connected to saidsliding plate by way of the guide bosses 16, 16 are moved to theterminal ends of their leftward strokes, as shown in FIGS. 1, 4 and 7,and thereafter a plurality of tape cartridges 2 are stacked in themagazine 3 with the lowermost one resting on the swinging arms 5, 5which are then in closed positions. Then, a prescribed voltage isimpressed across the powerterminals t,, shown in FIG. 21. A power sourcecurrent flows through a circuit composed of the fixed contact S and themovable contact S of the switch S, the switch S the drive motor M, andthe movable contact strip S and the fixed contact 5,,, of said switch S,so that the drive motor M is set in motion with the drive shaft mthereof rotating in a predetermined direction. The rotation of the driveshaft m is transmitted through the belt 13, the reduction gearing 14 andthe step gear 10 to the rack 7 to cause said rack to move to the rightslowly along with the sliding plate 9 and the U-shaped member 17. Thearms of the U-shaped member 17 go through the respective slots 3a, 3a,formed in the wall of the magazine 3, into said magazine to be locatedbetween the lowermost tape cartridge and the second one from the bottomof the cartridge stack as shown in FIG. 8.

In this case, the slant edge 24, of each hooking member 24, which ispivotally mounted on the boss 228 on the rocking member 22 on theunderside of the sliding plate 9, is brought into engagement with thedownwardly projecting pin 5A of the swinging arm 5 and as a result thehooking member 24 is caused to rotate in a clockwise direction, asviewed in FIG. 18, against the biasing force of the snap spring 25. Whenthe pin 5A slips off the slant edge of the hooking member, the hookingmember returns to its original position as shown in FIG. 20. Then, thedownwardly projecting bosses 9B of the sliding plate 9 come in abutmentagainst the upwardly bent lugs 20A of the respective swinging arms 20,and push the same as shown in FIG. 20. Therefore, the swinging arms 20,20 are rotated about the respective pivot pins 20,, 20 against the biasof the associated tension springs 21, 21 and brought to open positionsas indicated by the chain lines in FIG. 20 and by the dotted lines inFIG. 5. In this case, the lowermost tape cartridge 2 is still held onthe swinging arms 5, 5 and no tape cartridge is present on the swingingarms 20, 20.

As the rack 7 is further moved to the right, the switch-actuatingprojection 7A moves the switching strip 5,, of the switch S from thesolid-line position to the dotted line position in FIG. 21, changing thedirection of current flowing through the drive motor M. The drive motorrotates in a reverse direction and accordingly the sliding plate 9begins to be moved to the left slowly. Therefore, the upwardly bent lugs20A of the swinging arms 20, 20 are released from engagement with thedownwardly projecting bosses 9B, 9B of said sliding plate, and theswinging arms 20, 20 are again brought into the closed position as shownin FIGS. 6 and 19 under the bias of the associated tension springs 21,21. As the sliding plate 9 moves further leftwardly, the hooking edges24, of the hooking members 24 are brought into engagement with the pins5A, 5A of the respective swinging arms 5, 5, extending downwardly of thebaseplate 1 through the respective slots 11), 1b, and push said pins, sothat the swinging arms 5, 5, which have been in the closed position asshown in FIG.. 5, are rotated about the respective pivot pins 5,, 5, inan opening direction and assume the open position as shown in FIGS. 6and 19. Consequently, only the lowermost of the tape cartridges 2, 2resting on said swinging arms 5, 5 is allowed to drop gravitationallythrough the guide hole 4a in the mounting guide plate 4 and therectangular hole 1a in the baseplate 1 into the tape-cartridge-receivinghole in the sliding plate 9 by being guided by the downwardly bent lugs4A of said mounting guide plate and the upwardly bent lugs 18A, 18A ofthe guide member 18, and rests on the closed swinging arms 20, 20. Inthis case, the tape cartridges 2, 2, other than the lowermost one, areretained in the magazine 3 by the arms of the U- shaped member 17 asshown in FIG. 8. The tape cartridge 2 dropped from the magazine 3 isloosely held between the confronting downwardly bent lugs 9A, 9Adefining the tape-cartridge-receiving hole in the sliding plate 9, andcarried towards the guide plate 19 slowly as said sliding plate movesleftwardly, while sliding on the swinging arms 20, 20 as shown in FIG.7. In this case, since the leftward displacement of the pins 5A, 5A inengagement with the hooking edges 24 of the respective hooking members24 are restricted by the terminal ends of the respective slot lb, lbthrough which said pins extend, the rocking members 22 having saidhooking members pivotally connected thereto respectively are rotated bybeing pushed by the downwardly bent lugs 24A, 24A of said hookingmembers against the bias of the tension springs 23 as shown in FIG. 19.When the hooking edges 24, are disengaged from the respective pins 5A,5A, the swinging arms 5, 5 are returned to their closed positions asshown in FIGS. 4 and 17. The U- shaped member 17 also moves to the leftslowly by being carried by the sliding plate 9 and finally the arms ofsaid U-shaped member are cleared from the magazine 3 as shown in FIGS. 4and 7. Therefore, the stack of tape cartridges 2, 2 in the magazine dropall at once gravitationally for a height equivalent to the thickness ofone cartridge through the hole 40 in the mounting guide plate 4 by beingguided by the downwardly bent lugs 4A, and rest on the closed swingingarms 5, 5 on the baseplate l as shown in FIG. 7. When the sliding plate9 has been moved to the position shown in FIGS. 4 and,7, with the tapecartridge 2 therein located in a prescribed position al the guide plate19, that is the position in which the magnetic tape in the cartridge isheld in pressure contact with the magnetic head H, the switching strip Sfor the drive motor control switch S is switched from the dotted lineposition to the solid-line position by the switch-actuating projection78 on the rack 7 as shown in FIGS. 4 and 21', thereby providing for therotation of the drive motor M in a reverse direction to cause a returnmovement of the rack 7 and the sliding plate 9. Immediately thereafter,an actuating plunger 8,, of the switch S which is fixedly mounted on thebaseplate adjacent to the left-side end of the elongate slot M in saidbaseplate, is pressed in by the guide boss 16 on the sliding plate 9,opening said switch as indicated by the dotted line in FIG. 21, so thatthe current supply to the drive motor M is interrupted and the driveshaft m of said motor stops its rotation. Therefore, the sliding plate 9is brought to a halt with the magnetic tape (not shown) in the tapecartridge 2 in pressure contact with the slit surface I: of the magnetichead H. Thereafter, the tape cartridge 2 is fitted at its mounting holes2a on respective driving members, such as rotary shafts of theconventional type located below the guide plate 19 and the magnetic tapein said cartridge is driven in a predetermined direction at apredetermined rate while being held in pressure contact with the slitsurface h of the magnetic head H for playing or recording.

Upon completion (or in the middle) of the playing or recording, theoperation of the tape recorder is stopped either manually orautomatically. The tape cartridge 2 is disengaged from the tape recorderand the switch 5,, is temporarily closed manually or automatically as bymeans of a relay so arranged as to be actuated by a conductive memberprovided at the terminal end of the magnetic tape. A current is againconducted through the drive motor M through the switch S to drive saidmotor. In this case, however, since the direction of rotation of thedrive motor is reversed by virtue of said switch S, the rack 7 and thesliding plate 9 are moved to the right, so that the used tape cartridge2 is slowly carried away from the magnetic head H rightwardly in saidsliding plate. In the meantime, the guide boss 16 is detached from theactuating plunger S, of the switch 8,, closing said switch again topermit the power source current to be continuously supplied to the drivemotor therethrough. When the sliding plate 9 has moved rightwardly toits original-position shown in FIGS. 5 and 8, carrying the usedcartridge 2 therein, said tape cartridge rides on the closed swingingarms 20, 20 on the guide member 18. Then, the downwardly projectingbosses 9B, 93 on the sliding plate 9 push the upwardly bent lugs 20A,20A of said swinging arms,

causing these swinging arms to swing to the open positions, indicated bythe dotted lines in FIG. 5, against the tension of the tension springs21, 21. The used tape cartridge 2 therefore drops gravitationally belowthe guide member 18 and is removed outside of the tape recorder. Then,the switching strip 5 of the switch S is moved to the solid-lineposition, shown in FIG. 21, by the switch-actuating projection 7A on therack 7 to reverse the rotation of the drive motor, so that the slidingplate 9 is moved to the left. Immediately before the downwardly bentlugs 9A of the sliding plate 9 are brought in alignment with thecorresponding downwardly bent lugs 4A of the mounting guide plate 4during the leftward movement of the sliding plate 9, the hooking edges24 of the hooking members 24 on the underside of the sliding plate arebrought into engagement with the downwardly projecting pins 5A, 5A ofthe respective swinging arms 5, 5 which are then closed as shown in FIG. 5, and thereby said swinging arms are caused to make a pivotalmovement about the respective pivot pints 5 5, to assume the openpositions as shown in FIGS. 6 and 19. Upon opening of the swinging arms5, 5, the lowermost one only of the tape cartridges 2, 2 in the magazine3 drops on the swinging arms 20, 20, and the rest of the cartridges areretained in said magazine by the arms of the U-shaped member I7projecting into said magazine. The tape cartridge thus placed on theswinging arms 20, 20 is carried to the playing or recording position bythe sliding plate 9 and played or recorded in exactly the same manner asdescribed previously.

In the manner described hereinabove, it is possible, by the use of theinventive tape cartridge automatic exchange device,

to play or record a number of tape cartridges stacked in the magazineone after another successively and automatically in a stable andpositive manner without requiring any manual operation. Therefore, thefriction device is highly suitable for use as a music programsource or aBGM source at a wirebroadcast station. The device of this invention isalso useful as an endless tape cartridge automatic exchange device forthe conventional endless tape automatic players, e.g. a Lear jettypeautomatic player. As such, the device of this invention can be used inan extremely wide range of applications and is therefore of greatindustrial advantage.

Although in the embodiment described and illustrated herein, use is madeof the rack 7, gear 10 provided with the reduction gearing and the belt13 for the transmission of the drive of the motor to the sliding plate9, it is to be understood that a crank mechanism or a friction gearingsuing rubber discs, etc. may also be employed for the purpose.

We claim: I

1. An automatic tape cartridge changer in a tape recorder comprising afirst horizontal support means defining a first opening for passing acartridge therethrough; an open-ended magazine, for receiving a stack ofcartridges, mounted above said first opening; a first movable shutternormally closing said opening mounted on said support means forreleasably supporting said cartridge stack; a second horizontal supportmeans defining a second opening for passing a cartridge therethroughmounted below and spaced from said first support means a distancegreater than the thickness of a cartridge; a second movable shuttermounted on said second support means for normally closing said secondopening;

a cartridge retainer movably supported between said first and secondsupport means; a cartridge stack support movably mounted above said fistsupport means for selective engagement with said cartridge stack;coupling means linking said cartridge retainer and said cartridge stacksupport for synchronous movement thereof; an electrically actuated drivemeans for reciprocally moving said coupling means, said cartridgeretainer being moved from a cartridge-receiving position below saidfirst opening to a record-replay position laterally offset from saidreceiving position, then to a cartridge disposal position above saidsecond opening and then to the mentioned position, said cartridge stacksupport being moved into engagement with said stack for supporting allbut the lowermost cartridge above said first shutter when said cartridgeretainer is moved into said cartridge-receiving position; means linkedwith said coupling means for synchronous operation with said cartridgeretainer opening said first and second shutters when said cartridgeretainer is moved to said receiving and disposal positions,respectively, said cartridge retainer receiving the lowermost cartridgeof said stack when said first shutter is opened, said cartridge retainerreleasing said cartridge through said second opening when said secondshutter is opened; means for sensing the end of play of a tape cartridgeat said record-replay position to activate said driving means for movinga cartridge disposed in said cartridge retainer to said disposalposition, then to said cartridge-receiving position, and then back tothe record replay position.

2. An automatic tape cartridge changer as set forth in claim 1, whereinsaid coupling means is a slide plate and said driving means includes anelectric motor, a control circuit therefore, a first switch for turningoff or on the motor current which is arranged to be turned off by anactuator attached to said slide plate when said cartridge retainer is atsaid record-replay position, second switch for changing the motorconnection so as to reverse the direction of rotation ofsaid motor,means linked with slide plate for actuating said switch when saidcartridge retainer comes to said record-replay position, a third switchof normally open type connected in parallel with said first switch andmeans for temporarily closing said third switch in response to saidsignal indicating the end of the playing of a tape.

3. An automatic tape cartridge changer as set forth in claim 2, whereinsaid first movable shutter comprises a pair of rotatable arms each ofwhich is normally urged to the closed position by a spring and saidopening means therefore is a hook member pivotally attached to a rockingmember which is attached on the underside of said slide plate, and saidsecond movable shutter comprises another pair of rotatable arms each ofwhich is normally urged to the closed position by a spring and saidopening means therefor is a boss extending downwardly from said slideplate.

1. An automatic tape cartridge changer in a tape recorder comprising afirst horizontal support means defining a first opening for passing acartridge therethrough; an open-ended magazine, for receiving a stack ofcartridges, mounted above said first opening; a first movable shutternormally closing said opening mounted on said support means forreleasably supporting said cartridge stack; a second horizontal supportmeans defining a second opening for passing a cartridge therethroughmounted below and spaced from said first support means a distancegreater than the thickness of a cartridge; a second movable shuttermounted on said second support means for normally closing said secondopening; a cartridge retainer movably supported between said first andsecond support means; a cartridge stack support movably mounted abovesaid fist support means for selective engagement with said cartridgestack; coupling means linking said cartridge retainer and said cartridgestack support for synchronous movement thereof; an electrically actuateddrive means for reciprocally moving said coupling means, said cartridgeretainer being moved from a cartridge-receiving position below saidfirst opening to a record-replay position laterally offset from saidreceiving position, then to a cartridge disposal position above saidsecond opening and then to the mentioned position, said cartridge stacksupport being moved into engagement with said stack for supporting allbut the lowermost cartridge above said first shutter when said cartridgeretainer is moved into said cartrIdge-receiving position; means linkedwith said coupling means for synchronous operation with said cartridgeretainer opening said first and second shutters when said cartridgeretainer is moved to said receiving and disposal positions,respectively, said cartridge retainer receiving the lowermost cartridgeof said stack when said first shutter is opened, said cartridge retainerreleasing said cartridge through said second opening when said secondshutter is opened; means for sensing the end of play of a tape cartridgeat said record-replay position to activate said driving means for movinga cartridge disposed in said cartridge retainer to said disposalposition, then to said cartridge-receiving position, and then back tothe record replay position.
 2. An automatic tape cartridge changer asset forth in claim 1, wherein said coupling means is a slide plate andsaid driving means includes an electric motor, a control circuittherefore, a first switch for turning off or on the motor current whichis arranged to be turned off by an actuator attached to said slide platewhen said cartridge retainer is at said record-replay position, secondswitch for changing the motor connection so as to reverse the directionof rotation of said motor, means linked with slide plate for actuatingsaid switch when said cartridge retainer comes to said record-replayposition, a third switch of normally open type connected in parallelwith said first switch and means for temporarily closing said thirdswitch in response to said signal indicating the end of the playing of atape.
 3. An automatic tape cartridge changer as set forth in claim 2,wherein said first movable shutter comprises a pair of rotatable armseach of which is normally urged to the closed position by a spring andsaid opening means therefore is a hook member pivotally attached to arocking member which is attached on the underside of said slide plate,and said second movable shutter comprises another pair of rotatable armseach of which is normally urged to the closed position by a spring andsaid opening means therefor is a boss extending downwardly from saidslide plate.